In this example, the Elemental Estimate layout and grouping of items will be used. There are principles that you have to follow when building up composite rates for Approximate Quantities. We are going to illustrate a composite rate build-up for Ground Floor Construction:

First, you have to determine the Group unit of measurement. When you are measuring Ground Floor Construction in Elemental or Approximate Quantities estimating, the group unit of measurement is the square metre (m2).

Step 2

The second step is listing all associated Bill items that can be mapped to Floor Construction by area. These are:

Topsoil excavation – (m2) Rate – 5.00

Surface concrete bed – (m3) Rate – 1200

Mesh wire reinforcement – (m2) Rate – 125.00

DPM – (m2) Rate – 7.00

Sand blinding under floors – (m2) Rate – 35.00

Hardcore filling – (m3) Rate – 40

Ground compaction – (m2) Rate – 5.00

Ant proofing – (m2) Rate – 7.00

Striking off and floating top surface – (m2) Rate – R10

Ceramic floor tiles – (m2) Rate – R250

Screeds – (m2) Rate – R30

Step 3

Since your Group unit is the square metre (m2), you should convert the Bill item rates to Cost per Square Metre.